Process for breaking petroleum emulsions



Patented Sept. 8, 1942 PROCESS FOR BREAKING PETROLEUM EMULSIONS MelvinDe Groote, University City, and Bernhard Kelser, Webster Groves, Mm,asslgnors to lPetrolite Corporation, Ltd., Wilmington, Del., acorporation of Delaware No Drawing. Application March 21, 1941, SerialNo. 384,594

Claims. (01. 252-440) This invention relates primarily to the resolutionof petroleum emulsions.

The main object of our invention is to provide a novel process forresolving petroleum emulsions emulsion.

inorganic salts, from pipeline oil.

kylene glycol of the kind hereinafter over six carbon atoms.

by the following formula:

by materials of formula the polyalkylene glycols employed may beindicated by the following formula:

HOOC.D.COO.T'

Similarly,

Succinic acid or the anof the water-in-oil type, that are commonly re- 5in which m has its previous significance and 11. ferred to as cut oil,roily oil, emulsified represents a numeral varying from 2 to 4. oils,"etc., and which comprise fine droplets of Thus, the bulk of thedemulsifying materials naturally-occurring waters or brines dispersed inherein described, may be indicated within cera more or less permanentstate throughout the tain variations, as hereinafter stated, by theneuoil which constitutes the continuous phase of the i0 tral esterderived by esterification of one mole of a glycol of the kind abovedescribed, with two Another object is to provide an economical and molesof a fractional ester of the kind previously rapid process forseparating emulsions which described. The formation of the compound mayhave been prepared under controlled conditions be indicated by thefollowing reaction, although from mineral oil, such as crude petroleumand obviously, it is immaterial what particular prorelat'ively softwaters or weak brines. Controlled cedure is employed to produce theparticular emulsification and subsequent demulsification chemicalcompound or product: under the conditions just mentioned is ofsignificant value in removing impurities, particularly 0 The newchemical compound or composition T.OOC.D.COO(C2H4O)m-1CZH4.OOC.D.COO.Tof matter herein described, which is used as the As indicatedpreviously, the polybasic acids demulsifier in our improved process forresolvemployed are limited to the type having not ing petroleumemulsions, is exemplified by the more than six carbon atoms, forexample, oxacidic, or referably, neutral ester derived by alic,malonic,succinic, glutaric, and adipic. Simcomplete esterification ofone mole of a polyalilarly, one may employ acids such as fumaric,described, maleic, glutaconic, and various others, including with twomoles of a fractional ester derived from citric, malic, tartaric, andthe like. The seleca hydroxylated material of the kind herein detion ofthe particular tribasic or dibasic acid emscribed, and a polybasiccarboxy acid having not 30 ployed is usually concerned largely withconvenience of manufacture of the finished ester, and If a hydroxylatedmaterial, indicated for the also of the price of the .reactants.Generally sake of convenience by the formula I.OI-l, is respeaking, thehigher the temperature employed, acted with a olybasie cal-boxy acid,which, simthe easier it is to obtain large yields of the esteriiarly,may conveniently be indicated as being of ified product. Although oxalicacid is comparathe dibasic type, by the formula HOOC.D.COOI-I, Livelycheap, it decomposes somewhat readilyat then the fractional esterobtained by reaction slightly above the boiling point of Water. Forbetween equimolar quantities may be indicated this reason, it is moredesirable to use an acid which is more resistant to pyrolysis. 40 when apolybasic acid is available in the form HOOCD-COO-T of an anhydride,such anhydride is apt to produce the ester with greater ease than theacid The Polyethylene glycol may be charactenzed itself. For thisreason, maleic anhydride is parthe kind Such as heptaethylene ticularlyadaptable; and also, everything else glycol, octaethylene glycol,nonaethylene glycol, considered the cost is comparatively 1ow on adecaethylene glycol, to and including heptadecamolar basis even thoughsomewhat higher ethylene glycol. For convenience these polyethon a perpound bash ylene glycols may be indicated by the followmg hydride hasmany of the attractive qualities of maleic anhydride; and this is alsotrue of adipic OH(C2H40)mH acid. For purposes of brevity, the bulk ofthe the broadest aspect,

compounds hereinafter illustrated will-refer to the use of maleicanhydride, although it is understood that any other suitable polybasicacid may be employed. Furthermore, for purposes of convenience,reference is made to the use of polyethylene glycols. As has beenpreviously indicated. such glycols can be replaced by suitablepolypropylene or polybutylene compounds.

.As far as the range of oxyalkylated compounds employed as reactants isconcerned, it is our preferenceto employ those having approximately 8-12oxyalkylene groups, particularly 8-12 oxyethylene groups. The preferenceto use the oxyethylated compounds is due largelyto the fact that theyare commercially available, and particularly so in two desirable forms.The most desirable form is the so-called nonaethylene glycol, which.although consisting largely of nonaethylene glycol, may contain smallamounts of heptaethylene and octaethylene glycols, and pos sibly minorpercentages of the higher homologs. Such glycols represent the upperrange of distillable glycols; and they may be conveniently referred toas upper distillable ethylene glycols There is no particularly goodprocedure for making a sharper separation on a commercial scale; and itis understood that mixtures of one or more of the glycols may beemployed, as Well as a single glycol. As pointed out, it is particularlypreferred to employ nonaethylene glycol as commercially available,although it is understood that this product contains other homologs, asindicated.

Substantially as desirable as the upper distillable polyethyleneglycols, are the lower non-distillable polyethylene glycols. Thesematerials are available in the form of a waxy water-soluble material,and the general range may vary some- 'what from decatotetradeca-ethylene glycol. 'As is well understood, the method ofproducing such glycols would cause. some higher homologs to be formed;and thus, even in this instance. there may be present some oxy-ethyleneglycols within the higher range above indicated. One need not point outthat these particular compounds consist of mixtures, and that in someinstances, particularly desirable esters are obtained by making mixturesof the liquid nonaethylene glycol with the soft, waxy, lowernon-distillable polyethylene glycols. For the sake of convenience,reference in the examples will be to nonaethylene glycol; andcalculations will be based on a theoretical molecular weight of 414.Actually, in manufacture the molecular weight of the glycol employed,whether a higher distillable polyethylene glycol or a lowernon-distillable polyethylene glycol, or a mixture of the same, should bedetermined and reaction conducted on the basis of such determination,particularly in conjunction with the hydroxyl or acetyl value.

It has been previously pointed out that it is immaterial how thecompounds herein contemplated are manufactured, although we have foundit most desirable to react the selected glycol or mixtures of glycolswith maleic anhydride in a ratio of two moles of the anhydride for onemole of the glycol. Under such circumstances, we have found littletendency to form longer chain polymers; and in fact, the product ofreaction, if conducted at reasonably low temperatures, appears to belargely monomeric. For convenience, such intermediate product may thenbe considered as a dibasic or polybasic acid. One mol of theintermediate so obtained is then reacted with two moles of the alcoholicmaterial of the kind subsequently described.

It is to be noted, however, that if one prepares a fractional acidicester, then if two moles of the fractional acidic ester are reacted withone mole of the polyethylene glycol, there is no possibility for theformation of polymeric types of esteriflcation products under ordinaryconditions.

The alcoholic compounds employed as reactants in one mode of manufactureof the present compounds, are fractional esters obtained by reactionbetween detergent-forming acids and polyhydric alcohols.

Detergent-forming acids are monocarboxy acids having more than 8 and notover 32 carbon atoms, and characterized by the fact that they combinewith alkalies such as caustic soda, caustic potash, ammonia,triethanolamine, and the like, to producesoap or soap-like materials.The best examples are, of course, the higher fatty acids, such as oleicacid, stearic acid, palmitic acid, etc. In addition to the higher fattyacids, other well knowm members of this class include resinic acids,abietic acids, naphthenic acids, and acids obtained by the oxidation ofpetroleum hydrocarbons and commonly referred to as oxidized wax acids.

Generally speaking, the higher fatty acids are apt to contain from 12-14carbon atoms as a lower limit, to 18-22 carbon atoms as an upper limit.OxidLed wax acidsmay contain as many as 32 carbon atoms. For the sake ofbrevity, reference will be made to superglycerinated fats, although itis understood that similar products obtained from otherdetergent-forming acids, as well as fatty acids, are just as acceptable.

Superglycerinated fats can be prepared by a number of well knownprocedures. One procedure is to react the fatty acid with a suitablepolyhydric alcohol. Another procedure is to react an ester, forinstance, a glyceride, with an excess of glycerol. Such procedure issometimes referred to as reesterification. Other procedures include theuse of ethylene oxide, ethylene chlorhydrin, glycerol monochlorhydrin,or the like. Since the manufacture of these products is well known,particularly in view of their utility in a number of industries, it doesnot appear that further comment is required. However, attention isdirected to a trade pamphlet entitled Polyhyclric alcohol esters,"issued by the Glyco Products Company, 1940. This pamphlet describesnumerous fractional esters derived from fatty acids which areparticularly adaptable for use as reactants in the present instance.

The materials herein contemplated may be illustrated further by thefollowing examples:

Intermediate product, Example 1 One pound mole of nonaethylene glycol isreacted with two pound moles of maleic anhydride,

so as to form nonaethylene glycol dihydrogen dimaleate.

Intermediate product, Example 2 Intermediate product, Example 3 A 50-50mixture of nonaethylene glycol and lower non-distillable polyethyleneglycols of the kind described in the previous example is substituted fornonaethylene glycol in Example 1.

Intermediate product, Example 4 Adipic acid is substituted for maleicanhydride in Examples 1-3 preceding. 1

Intermediate product, Example Oxallc acid is substituted for nialeicanhydride in Examples 1-3 preceding.

Intermediate product, Example 6 Citric acid is substituted for maleicanhydride in Examples 1-3 preceding.

Intermediate product, Example 7 Succinic anhydrlde is substituted formaleic anhydride in Examples 1-3 preceding.

The method of producing such fractional esters is well known. Thegeneral procedure is to employ a temperature above the boiling point ofwater and below the pyrolytic point of the reactants. The products aremixed and stirred constantly during the heating and esteriflcation step.If desired, an inert gas, such as dried nitrogen, or dried carbondioxide, may be passed through the mixture. Sometimes it is desirable toadd an esterificationcatalyst, such as sulfuric acid, benzene sulfonicacid, or the like. This is the same general procedure as employed in themanufacture of ethylene glycol dihydrogen diphthalate. See U. S. PatentNo. 2,075,107, dated March 30, 1937, to Frasier.

. Sometimes esterification is conducted most readily in the presence ofan inert solvent, that carries away the water of esterification whichmay be formed, although, as is readily appreciated, such water ofesterification is absent when the reaction involves an acid anhydride,such as maleic anhydride, and a glycol. However, if water is formed, forinstance, whencitric acid is employed, then a solvent such asxylene maybe present and employed to carry off the water formed. The mixture ofxylene vapors and water vapors can be condensed so that the water isseparated. The xylene is then returned to the reaction vessel forfurther circulation. This is a conventional and well-known procedure andrequires no further elaboration.

Composition of matter, Example 1 One pound mole of the intermediateproduct of the kind described in Intermediate product, Examples 1, 2 and3, above, is reacted with two pound moles of diethylene glycolmonolaurate until all carboxyl acidity has disappeared. Time of reactionmay vary from a few hours to as much as hours.

Compositi n of matter, Example 2 Diethylene glycol monomyristate issubstituted for diethylene glycol monolaurate in the precedfillComposition of matter, Example 7 Diethylene glycol glyceryl monostearateis substituted for diethylene glycol monolaurate in Composition ofmatter, Example 1.

Composition of matter, Example 8 Ethylene glycol mono-oleate issubstituted for diethylene glycol monolaurate in Composition of matter,Example 1.

Composition of matter, Example 9 Ethylene glycol monoricinoleate issubstituted for diethylene glycol monolaurate in Composition of matter,Example 1.

Composition of matter, Example 10 Glyceryl monolaurate is substitutedfor diethylene glycol monolaurate in Composition of matter, Example 1.

Composition of matter, Example 11 Glyceryl mono-oleate is substitutedfor diethylene glycol monolaurate in Composition of matter, Example 1.

Composition of matter, Example 12 The'same procedure is followed as inComposition of matter, Examples 1-11, inclusive, except thatintermediate product of the kind exemplifled by Intermediate product,Example 4, is substituted for that in Intermediate product, Exam ples l,2 and 3.

Composition of matter, Example 13 The same procedure is followed as inComposition of matter, Examples 1-11, inclusive, exce t thatintermediate product of the kind exemplified by Intermediate product,Example 5, is substituted for that in Intermediate product, Examples 1,2 and 3.

Composition of matter, Example 14 The same procedure is followed as inComposition of matter, Examples 1-1l, inclusive, except thatintermediate product of the kind exemplifled by Intermediate product,Example 6, is substituted for that in Intermediate product, Examples 1,2 and 3.

Composition of matter, Example 15 esterification reaction, and the sameprocedure is employed assuggested above in the preparation of theintermediate product. Needless to say, any particular method may be usedto produce the desired compounds of the kind indicated. In someinstances it may be desirable to conduct the esterification reaction inpresence of a non-volatile inert solvent, which simply acts as a diluentor viscosity reducer.

In the preceding examples, attention has been directed primarily to themonomeric form or at least to the form in which the biiunctionalalcohol, i. e., a glycol, and the polyfunctional acid, usually abifunctional compound, react to give a chain type compound, in which theadj acent acid and glycol nucleus occur as a structural unit.

For instance, in the monomeric form this may be indicated in thefollowing manner:

acid glycol acid acid glycol acid glycol acid Similarly, three moles ofthe glycol and four moles of the acid might tend to give a combinationwhich may be indicated thus:

acid glycol acid glycol acid glycol acid Another Way of stating thematter is that the composition may be indicated in the following manner:

in which the characters have their previous significance and a: is arelatively small whole number less than 10 and probably less than 5; andin the monomeric form :r, of course, is l. The limitations on the sizeof :c are probably influenced largely by the fact that reaction leadingto further growth is dependent upon random contact. Some of the productsare self-emulsifiable oils or self-emulsifiable compounds; whereas,others give cloudy solutions or sols; and the most desirable type ischaracterized by giving a clear solution in water, and usually in thepresence of soluble calcium or magnesium salts, and frequently, in thepresence of significant amounts of either acids or alkalies.

Water solubility can be enhanced in a number of ways which have beensuggested by previous manufacturing directions, for instance:

(a) By using a more highly polymerized ethylene glycol;

(b) By using a polymeric form instead of a monomeric form in regard tothe unit which forms the chain between the two alcoholic nuclei;

(c) By using a polybasic carboxy acid of lower molecular Weight, forinstance, maleic acid instead of adipic acid;

(d) By using an alcoholic material of lower molecular weight, forinstance, ethylene glycol monolaurate, instead of ethylene glycolmonostearate;

(e) By using a material such as diethylene glycol mono-oleate orglyceryl mono-oleate, instead of ethylene glycol mono-oleate.

In any event, it is to be noted that the compounds of the type hereincontemplated are limited to the water-soluble type, i. e., those whichare self-emulsifying in water, or produce a sol or a molecular solution.

Incidentally, one obvious fact may be conveniently emphasized at thispoint; and that is that the hydroxylated aliphatic esters of thedetergent-forming acids employed to combine with nonaethylene glycoldihydrogen dimaleate or similar materials, must be of thewater-insoluble type. In other words, it is not intended to includeesters of the kind obtained by reaction of ethylene oxide on olelc acidor the like with the formation of a large number of recurring etherlinkages so as to obtain water solubility.

It is to be noted that the higher fatty acids include blown fatty acids,or superglycerinated esters obtained from blown oils. As to the specificdescription of this-particular type of material which may be used as areactant, see U. S. Patent No. 2,208,509, dated July 16, 1940, to Blairand Boydstun.

As herein used, the term polyhydric alcohol" refers to aliphaticalcohols containing two or more hydroxyl groups, and is intended toinclude such compounds as glycerol, ethylene glycol, beta-methylglycerol, 1,3 propanediol, pentamethylene glycol, alpha, beta, gammapentanetriol, sorbitol, mannitohand the like, and also the polyhydroxyether alcohols, such as diglycerol,

triglycerol, tetraglycerol, diethylene glycol, etc. Such polyhydricether alcohols may also be produced by ether formation from two on moredifferent polyhydric alcohols to yield compounds, such as ethyleneglycol monoglyceryl ether, 1,3 propanediol monoethylene glycol ether,diethylene glycol monoglyceryl ether, etc. Suitable polyhydroxy etheralcohols may also be produced from a polyhydric alcohol containing threeor more hydroxyls and a monohydric alcohol. Examples of such compoundsare glycerol monobutyl ether, glycerol monoallyl ether, pentanetriolmonoethyl ether, diglycerol monopropyl ether, etc. Actually, a reactioninvolving an alcohol and an acid (esteriflcation) may permit smallamounts of either one or both of the reactants, depending upon thepredetermined proportion, to remain in an unreacted state. In the actualpreparation of compositions of the kind herein contemplated, anyresidual acidity can be removed by any suitable base, for instance,ammonia, triethanolamine, or the like, especially in dilute solution.

neutralization takes place without saponification or decomposition ofthe ester. In some cases there is no objection to the presence of theacidic group, Indeed, if a tribasic acid be employed in such a manner asto leave one free, carboxyl group, then it is usually desirable toneutralize such group by means of a suitable basic material, In thehereto appended claims, reference to a neutral product refers to one inwhich 'free carboxylic radicals are absent.

Conventional demulsifying agents employed in the treatment of oil fieldemulsions are used as such, or after dilution with any suitable solvent,such as water; petroleum hydrocarbons, such as gasoline, kerosene, stoveoil, a coal tar product, such as benzene, toluene, xylene, tar acid oil,cresol, anthracene oil, etc. Alcohols, particularly aliphatic. alcohols,such as methyl alcohol, ethyl alcohol, denatured alcohol, propylalcohol, butyl alcohol, hexyl alcohol, octyl alcohol, etc., may beemployed as diluents. Miscellaneous solvents, such as pine oil, carbontetrachloride, sulfur dioxide extract obtained in the refining ofpetroleum, etc., may be employed as diluents. Similarly, the material ormaterials herein described, may be admixed with one or more of thesolvents customarily used in connection with conventional demulsifyingagents, provided that such limited oil solubility, However, since suchrea ents are sometimes used in a ratio of 1 to 10,000, or 1 to 20,000,or even 1 to 30,000, such an apparent insolubility in oil and water isnot significant, because said reagents undoubtedly have solubilitywithin the concentration employed. This same fact is true in regard tothe material or materials herein described, except that they areinvariably water-soluble.

We desire to point out that the superiority of the reagent ordemulsifying agent contemplated in our herein described process forbreaking petroleum emulsions, is based upon its ability to treat certainemulsions more advantageously and at a somewhat lower cost than ispossible with other available demulsifiers, or conventional mixturesthereof. It is believed that the particular demulsifying agent ortreating agent herein described will find comparatively limitedapplication, so far as the majority of oil field emulsions areconcerned; but we have found that such a demulsifying agent hascommercial value, as it will economically break or resolve oil fieldemulsions in a number of cases which cannot be treated as easily or atso low a cost with'the demulsifying agents heretofore available.

In practising our improved process for resolving petroleum emulsions ofthe water-in-oil type, a treating agent or demulsifying agent of thekind above described is brought into contact with 1 or caused to actupon the emulsion to be treated, in any of the various ways, or by anyof the various apparatus now generally used to resolve or breakpetroleum emulsions with a chemical reagent, the above procedure beingused either alone, or in combination with other demulsifying procedure,such a the electrical dehydration process.

The demulsifier herein contemplated may be employed in connection withwhat is commonly known as down-the-hole procedure, i. e., bringing thedemulsifier in contact with the fluids of the alkylene radical thereofcontaining at least 2 and not more than 6 carbon atoms; and (B) apolybasic carboxy acid having not more than 6 carbon atoms; and theratio of the esterifying reactants being within the range of more than 1and not over 2 moles of the polybasic acid for each mole of the glycol;and said water-insoluble polyhydric material being a hydroxylatedfractional ester derived by reaction between a detergent-formingmonocarboxy acid having more than 8 and not more than 32 carbon atoms,and a polyhydric al'cohol having at least 2 and not more than 12 carbonatoms.

2. A process for breaking petroleum emulsions of the water-in-oil type,characterized by subjecting the emulsion to the action of a demulsifyingagent comprising a neutral water-soluble esterification product derivedby reaction between one mole of a polybasic compound and two moles of awater-insolubl hydroxylated compound; the polybasic compound being theesterification product of (A) a polyalkylene glycol having at least 7and not more than 17'ether linkages, and the alkylene radical thereofcontaining at least 2 and not more than 6 carbon atoms; and (B) apolybasic carboxy acid having not more than 6 carbon atoms; and theratio of the esterifying reactants being within the range of more than 1and not over 2 moles Of the polybasic acid for each mole of the glycol;and said water-insoluble polyhydric material being a hydroxylatedfractional ester derived by reaction the well at the bottom of the well,or at some point prior to their emergence. This particulartype ofapplication is decidedly feasible when the demulsifier is used inconnection with acidification of calcareous oil-bearing strata,especially if suspended in or dissolved in the acid employed foracidification.

It will be apparent to those skilled in the art that residual carboxylacidity can be eliminated by esterification with a low molal alcohol,for instance, ethyl, methyl, or propyl alcohol, by conventionalprocedure, so as to give a substantially neutral product. Theintroduction of such low molal hydrophob groups does not seriouslyaffect the solubility, and in some instances gives increased resistance,to soluble calcium and magnesium salts, for such property is ofParticular value, Usually, however, neutralization with a dilutesolution of ammonia or the like is just as practicable and lessexpensive.

Having thus described our invention, what we claim as new and desire tosecure by Letters Patent is:

1. A process for breaking petroleum emulsions of the water-in-oil type,characterized by subjecting the emulsion to the action of a demulsifyingagent comprising a water-soluble esterification product derived byreaction between one mole of a polybasic compound and two moles of awater-insoluble hydroxylated compound; the polybasic compound being theesterification product of (A) a polyalkylene glycol having at least 7and not more than 17 ether linkages, and

between a detergent-forming monocarboxy acid having more than 8 and notmore than 32 carbon atoms, and a polyhydric alcohol having at least 2and not more than 12 carbon atoms.

3. A process for breaking petroleum emulsions of the water-in-oil type,characterized by subjecting the emulsion to the action of a demulsifyingagent comprising a neutral water-soluble esterification product derivedby reaction between one mole of a dibasic compound and two moles of awater-insoluble hydroxylated compound; the dibasic compound being theesterification product of (A) a polyalkylene glycol having at least 7and not more than 17 ether linkages, and the alkylene radical thereofcontaining at least 2 and not more than 6 carbon atoms; and (B) adibasic carboxy acid having not more than 6 carbon atoms; and the ratioof the esterifying reactants being within the range of more than 1 andnot over 2 moles of the dibasic acid for each mole of the glycol; andsaid water-insoluble polyhydric material being a hydroxylated fractionalester derived by reaction between a detergent-forming monocarboxy acidhaving more than 8 and not more than 32 carbon atoms, and a. polyhydricalcohol having at least 2 and not more than 12 carbon atoms.

4. A process for breaking petroleum emulsions of the water-in-oil type,characterized by subjecting the emulsion to the action of a demulsityingagent comprising a neutral water-soluble esterification product derivedby reaction between one mole of a dibasic compound and two moles of awater-insoluble hydroxylated compound; the dibasic compound being theesterification product of (A) a polyethylene glycol having at least 7and not more than 17 ether linkages; and (B) a dibasic carboxy acidhaving not more than 6 carbon atoms; and the ratio of the esterifyingreactants being within the range of more than 1 and not over 2 moles ofthe dibasic acid for each mole of the glycol; and said water-insolublepolyhydric material being a hydroxylated fractional ester derived byreaction between a detergent-forming mono-carboxy acid having more than8 and not more than 32 carbon atoms, and a polyhydric alcohol having atpound; the dibasic compound being the esterification product of (A) apolyethylene glycol having at least 7 and not more than 17 etherlinkages; and (B) a dibasic carboxy acid having not more than 6 carbonatoms; and the ratio of V the esterifying reactants being within therange of more than 1 and not over 2 moles of the 'clibasic acid for eachmole of the glycol; and said waterinsoluble polyhydric material being ahydroxylated fractional ester derived by reaction between a higher fattyacid having more than 8 and not over 32 carbon atoms, and a polyhydricalcohol having at least 2 and not more than 12 carbon atoms.

6. A process for breaking petroleum emulsions of the water-in-oil type,characterized by subjecting the emulsion to the action of a demulsifyingagent comprising a neutral Water-soluble chemical compound of thefollowing formula type:

in which T is a radical derived by the dehydroxylation of awater-insoluble hydroxylated fractiona1 ester derived by reactionbetween a higher fatty acid having more than 8 and not more than 32carbon atoms, and a polyhydric alcohol havin,which T is a radicalderived by the dehydroxylation of a water-insoluble hydroxylatedfractional ester derived by reaction between a higher fatty acid havingmore than 8 and not more than 32 carbon atoms, and a polyhydric alcoholhaving at least 2 and not more than 12 carbon atoms; OOC.D.C0O is theacid radical derived from a dibasic acid by removal or the acidichydrogen atoms; said acid radical having not over 6 carbon atoms; and121. represents a numeral varying from 7 to 12.

8. A process for breaking petroleum emulsions of the water-in-oil type,characterized by subjecting the emulsion to the action of a demulsifyingagent comprising a water-soluble chemical compound of the followingformula type:

in which T is a radical derived by the dehydroxylation of awater-insoluble hydroxylated fractional ester derived by reactionbetween a higher fatty acid having more than 8 and not more than 32carbon atoms, and a polyhydric alcohol having at least 2 and not morethan 12 carbon atoms; OOC.D.COO is the acid radical derived from maleicacid by removal of the acidic hydrogen atoms; and m represents a numeralvarying from 7 to 12.

9. A process for breaking petroleum emulsions of the water-in-oil type,characterized by sub jecting the emulsion to the action of ademulsifying agent comprising a water-soluble chemical compound of thefollowing formula type:

TOOC.D.COO ((321-) mC2H4OOC.D.COO.T

in which T is a radical derived by the denydroxylation of awater-insoluble hydroxylated fractional ester derived by reactionbetween a higher fatty acid having more than 8 and not more than 32carbon atoms, and a polyhydric alcohol having at least 2 and not morethan 12 carbon atoms; 00011000 is the acid radical derived from succinicacid by removal of the acidic hydrogen atoms; and m represents a numeralvarying from 7 to 12.

10. A process for breaking petroleum emulsions of the water-in-oil type,characterized by subjecting the emulsion to the action of a demulsi-'fying agent comprising a water-soluble chemical compound of thefollowing formula type:

TOOC.D.COO(C2H4O) mC2H4OOC.D.COO.T

in which T is a radical derived by the dehydroxylation of awater-insoluble hydroxylated fractional ester derived by reactionbetween a higher fatty acid having more than 8 and not more than32-carbon atoms, and a polyhydric alcohol having at least 2 and not morethan 12 carbon atoms; OOC.D.COO is the acid radical derived from adipicacid by removal of the acidic hydrogen atoms; and m represents a numeralvarying from 7 to 12.

MELVIN DE GROOTE. BERNHARD KEISER.

